#include<stdio.h>
int fingsignle(int arr[], int sz)
{
	int num = 0;
	for (int i = 0; i < sz; i++)
	{
		num ^= arr[i];
	}
	return num;
}
int main1()
{
	int arr[5] = { 1,2,3,1,2 };
	int sz = sizeof(arr) / sizeof(arr[1]);
	int ret = fingsignle(arr, sz);
	printf("%d\n", ret);
	return 0;
}

int main2()
{
	int a = 5;
	int b = 6;
	printf("%d %d\n", a, b);
	a = a ^ b;
	b = a ^ b;
	a = a ^ b;
	printf("%d %d\n", a, b);

	return 0;
}
